People have been wondering about the origin of light, electrons, and gravity
for very long time. Such a curiosity has driven the development particle
physics in last 100 years. In another field --modern condensed matter
physics, physicists have been trying to find new types of matter, so that they
can use the new materials to make new devices. It turns out that these two
seemly unrelated fields have a deep connection.

In early days of particle physics, our approach has been dominated by the
reductionist approach: to gain a deeper understanding of something,
we simply need to divide the thing into small parts. Thus to gain a deeper
understanding of photons and electrons and to understand the strange properties of
photons and electrons, we need to find a smaller parts of photons and
electrons. The different properties of a photon and an electron
may be due to their different internal structures.

However, this line of thinking may be fundamentally flawed. They are based on
the reductionist belief that the space is empty and that things placed in the
empty space are divisible. However, there are many examples from condensed
matter physics indicating that sometimes this line of thinking doesnot make sense.
For example, due to the particle-wave duality in quantumtheory, sound waves in a
solid correspond to a kind of particle called phonon. Phonons are as much
particle-like as any other elementary particles. But if we look at phonons
closely, we do not see smaller parts that form a phonon. We see the atoms
that form the entire solid. The